Many fluorinated surfactants are already known, and in particular quaternary ammonium salts in which a perfluorinated radical is linked to the quaternary ammonium group (for example trialkylammonium or pyridinium) by a bridge whose nature greatly affects the application properties. This bridge can be very simple, for example CH.sub.2 or C.sub.2 H.sub.4 (U.S. Pat. No. 2,727,923 and French Patent No. 1,588,482) or more complex, for example --C.sub.2 H.sub.4 SONH(CH.sub.2).sub.3 -- (French Patent No. 2,084,888) or --C.sub.2 H.sub.4 S(CH.sub.2).sub.3 --OCH.sub.2 CH(OH)CH.sub.2 -- (European Patent No. 256,980), and the like. The above references are hereby incorporated by reference.